From 53bcd6b4118c0cd9f2a95debc5897da9a3bb1381 Mon Sep 17 00:00:00 2001
From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Sun, 15 Dec 2013 19:13:37 +0100
Subject: [PATCH] Define and use new TMP_GMP_ALLOC macro.

---
 ChangeLog           | 21 +++++++++++++++++++++
 bignum-next-prime.c | 10 +++++-----
 bignum-random.c     | 10 ++++++----
 gmp-glue.c          | 25 ++++++++++++++++++++++++-
 gmp-glue.h          | 16 +++++++++++++++-
 pkcs1-decrypt.c     | 32 ++++++++++++++++++++++++--------
 pkcs1-encrypt.c     |  8 +++++---
 pkcs1-rsa-digest.c  | 12 +++++++++---
 pkcs1-rsa-md5.c     | 24 +++++++++++++++++-------
 pkcs1-rsa-sha1.c    | 24 +++++++++++++++++-------
 pkcs1-rsa-sha256.c  | 24 +++++++++++++++++-------
 pkcs1-rsa-sha512.c  | 24 +++++++++++++++++-------
 12 files changed, 177 insertions(+), 53 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8b6655dd..26037fc4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+2013-12-15  Nikos Mavrogiannopoulos <nmav@redhat.com>
+
+	Introduced TMP_GMP_ALLOC macro for temporary allocations of
+	potentially large data, e.g, sized as an RSA key.
+	* gmp-glue.h (TMP_GMP_DECL, TMP_GMP_ALLOC, TMP_GMP_FREE): New
+	macros.
+	* gmp-glue.c (gmp_alloc, gmp_free): New functions.
+	* bignum-next-prime.c (nettle_next_prime): Use TMP_GMP_ALLOC.
+	* bignum-random.c (nettle_mpz_random_size): Likewise.
+	* pkcs1-decrypt.c (pkcs1_decrypt): Likewise.
+	* pkcs1-encrypt.c (pkcs1_encrypt): Likewise.
+	* pkcs1-rsa-digest.c (pkcs1_rsa_digest_encode): Likewise.
+	* pkcs1-rsa-sha512.c (pkcs1_rsa_sha512_encode)
+	(pkcs1_rsa_sha512_encode_digest): Likewise.
+	* pkcs1-rsa-sha256.c (pkcs1_rsa_sha256_encode)
+	(pkcs1_rsa_sha256_encode_digest): Likewise.
+	* pkcs1-rsa-sha1.c (pkcs1_rsa_sha1_encode)
+	(pkcs1_rsa_sha1_encode_digest): Likewise.
+	* pkcs1-rsa-md5.c (pkcs1_rsa_md5_encode)
+	(pkcs1_rsa_md5_encode_digest): Likewise.
+
 2013-12-14  Niels Möller  <nisse@lysator.liu.se>
 
 	* x86_64/gcm-hash8.asm: Use .short rather than .hword, for
diff --git a/bignum-next-prime.c b/bignum-next-prime.c
index 58a4df8b..6358fb11 100644
--- a/bignum-next-prime.c
+++ b/bignum-next-prime.c
@@ -31,8 +31,7 @@
 #include <stdlib.h>
 
 #include "bignum.h"
-
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 /* From gmp.h */
 /* Test for gcc >= maj.min, as per __GNUC_PREREQ in glibc */
@@ -77,9 +76,8 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,
 		  void *progress_ctx, nettle_progress_func *progress)
 {
   mpz_t tmp;
-  TMP_DECL(moduli, unsigned, NUMBER_OF_PRIMES);
-  
   unsigned difference;
+  TMP_GMP_DECL(moduli, unsigned);
 
   if (prime_limit > NUMBER_OF_PRIMES)
     prime_limit = NUMBER_OF_PRIMES;
@@ -112,7 +110,8 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,
      between the 5760 odd numbers in this interval that have no factor
      in common with 15015.
    */
-  TMP_ALLOC(moduli, prime_limit);
+  TMP_GMP_ALLOC(moduli, prime_limit);
+
   {
     unsigned i;
     for (i = 0; i < prime_limit; i++)
@@ -159,4 +158,5 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,
 #endif
     }
   mpz_clear(tmp);
+  TMP_GMP_FREE(moduli);
 }
diff --git a/bignum-random.c b/bignum-random.c
index f305f040..16877363 100644
--- a/bignum-random.c
+++ b/bignum-random.c
@@ -30,7 +30,7 @@
 #include <stdlib.h>
 
 #include "bignum.h"
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 void
 nettle_mpz_random_size(mpz_t x,
@@ -38,15 +38,17 @@ nettle_mpz_random_size(mpz_t x,
 		       unsigned bits)
 {
   unsigned length = (bits + 7) / 8;
-  TMP_DECL(data, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(data, length);
+  TMP_GMP_DECL(data, uint8_t);
 
-  random(ctx, length, data);
+  TMP_GMP_ALLOC(data, length);
 
+  random(ctx, length, data);
   nettle_mpz_set_str_256_u(x, length, data);
 
   if (bits % 8)
     mpz_fdiv_r_2exp(x, x, bits);
+  
+  TMP_GMP_FREE(data);
 }
 
 /* Returns a random number x, 0 <= x < n */
diff --git a/gmp-glue.c b/gmp-glue.c
index a2633a50..f76c3411 100644
--- a/gmp-glue.c
+++ b/gmp-glue.c
@@ -3,7 +3,8 @@
 /* nettle, low-level cryptographics library
  *
  * Copyright (C) 2013 Niels Möller
- *  
+ * Copyright (C) 2013 Red Hat
+ *
  * The nettle library is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation; either version 2.1 of the License, or (at your
@@ -239,3 +240,25 @@ gmp_free_limbs (mp_limb_t *p, mp_size_t n)
 
   free_func (p, (size_t) n * sizeof(mp_limb_t));
 }
+
+void *
+gmp_alloc(size_t n)
+{
+  void *(*alloc_func)(size_t);
+  assert (n > 0);
+
+  mp_get_memory_functions(&alloc_func, NULL, NULL);
+
+  return alloc_func (n);
+}
+
+void
+gmp_free(void *p, size_t n)
+{
+  void (*free_func)(void *, size_t);
+  assert (n > 0);
+  assert (p != 0);
+  mp_get_memory_functions (NULL, NULL, &free_func);
+
+  free_func (p, (size_t) n);
+}
diff --git a/gmp-glue.h b/gmp-glue.h
index 269667f4..be3ff6e0 100644
--- a/gmp-glue.h
+++ b/gmp-glue.h
@@ -3,7 +3,8 @@
 /* nettle, low-level cryptographics library
  *
  * Copyright (C) 2013 Niels Möller
- *  
+ * Copyright (C) 2013 Red Hat
+ *
  * The nettle library is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation; either version 2.1 of the License, or (at your
@@ -65,6 +66,17 @@
 #define mpn_set_base256 _nettle_mpn_set_base256
 #define gmp_alloc_limbs _nettle_gmp_alloc_limbs
 #define gmp_free_limbs _nettle_gmp_free_limbs
+#define gmp_free _nettle_gmp_free
+#define gmp_alloc _nettle_gmp_alloc
+
+#define TMP_GMP_DECL(name, type) type *name;	\
+  size_t tmp_##name##_size
+#define TMP_GMP_ALLOC(name, size) do {					\
+    tmp_##name##_size = (size);						\
+    (name) = gmp_alloc(sizeof (*name) * (size));	\
+  } while (0)
+#define TMP_GMP_FREE(name) (gmp_free(name, tmp_##name##_size))
+
 
 /* Use only in-place operations, so we can fall back to addmul_1/submul_1 */
 #ifdef mpn_cnd_add_n
@@ -155,5 +167,7 @@ gmp_alloc_limbs (mp_size_t n);
 void
 gmp_free_limbs (mp_limb_t *p, mp_size_t n);
 
+void *gmp_alloc(size_t n);
+void gmp_free(void *p, size_t n);
 
 #endif /* NETTLE_GMP_GLUE_H_INCLUDED */
diff --git a/pkcs1-decrypt.c b/pkcs1-decrypt.c
index 02d37288..b92d92c9 100644
--- a/pkcs1-decrypt.c
+++ b/pkcs1-decrypt.c
@@ -31,42 +31,58 @@
 #include "pkcs1.h"
 
 #include "bignum.h"
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 int
 pkcs1_decrypt (size_t key_size,
 	       const mpz_t m,
 	       size_t *length, uint8_t *message)
 {
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
+  TMP_GMP_DECL(em, uint8_t);
   uint8_t *terminator;
   size_t padding;
   size_t message_length;
+  int ret;
 
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_ALLOC(em, key_size);
   nettle_mpz_get_str_256(key_size, em, m);
 
   /* Check format */
   if (em[0] || em[1] != 2)
-    return 0;
+    {
+      ret = 0;
+      goto cleanup;
+    }
 
   terminator = memchr(em + 2, 0, key_size - 2);
 
   if (!terminator)
-    return 0;
+    {
+      ret = 0;
+      goto cleanup;
+    }
   
   padding = terminator - (em + 2);
   if (padding < 8)
-    return 0;
+    {
+      ret = 0;
+      goto cleanup;
+    }
 
   message_length = key_size - 3 - padding;
 
   if (*length < message_length)
-    return 0;
+    {
+      ret = 0;
+      goto cleanup;
+    }
   
   memcpy(message, terminator + 1, message_length);
   *length = message_length;
 
-  return 1;
+  ret = 1;
+cleanup:
+  TMP_GMP_FREE(em);
+  return ret;
 }
 	       
diff --git a/pkcs1-encrypt.c b/pkcs1-encrypt.c
index 69ef5bcf..86fb7b85 100644
--- a/pkcs1-encrypt.c
+++ b/pkcs1-encrypt.c
@@ -34,7 +34,7 @@
 #include "pkcs1.h"
 
 #include "bignum.h"
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 int
 pkcs1_encrypt (size_t key_size,
@@ -43,7 +43,7 @@ pkcs1_encrypt (size_t key_size,
 	       size_t length, const uint8_t *message,
 	       mpz_t m)
 {
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
+  TMP_GMP_DECL(em, uint8_t);
   size_t padding;
   size_t i;
 
@@ -63,7 +63,7 @@ pkcs1_encrypt (size_t key_size,
   padding = key_size - length - 3;
   assert(padding >= 8);
   
-  TMP_ALLOC(em, key_size - 1);
+  TMP_GMP_ALLOC(em, key_size - 1);
   em[0] = 2;
 
   random(random_ctx, padding, em + 1);
@@ -77,5 +77,7 @@ pkcs1_encrypt (size_t key_size,
   memcpy(em + padding + 2, message, length);
 
   nettle_mpz_set_str_256_u(m, key_size - 1, em);
+
+  TMP_GMP_FREE(em);
   return 1;
 }
diff --git a/pkcs1-rsa-digest.c b/pkcs1-rsa-digest.c
index debfb289..674ed9b6 100644
--- a/pkcs1-rsa-digest.c
+++ b/pkcs1-rsa-digest.c
@@ -29,21 +29,27 @@
 #include "pkcs1.h"
 
 #include "bignum.h"
+#include "gmp-glue.h"
 #include "nettle-internal.h"
 
 int
 pkcs1_rsa_digest_encode(mpz_t m, size_t key_size,
 			size_t di_length, const uint8_t *digest_info)
 {
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   if (_pkcs1_signature_prefix(key_size, em,
 			      di_length, digest_info, 0))
     {
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
diff --git a/pkcs1-rsa-md5.c b/pkcs1-rsa-md5.c
index b118b4f3..d48a57d1 100644
--- a/pkcs1-rsa-md5.c
+++ b/pkcs1-rsa-md5.c
@@ -36,7 +36,7 @@
 #include "bignum.h"
 #include "pkcs1.h"
 
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 /* From pkcs-1v2
  *
@@ -65,8 +65,9 @@ int
 pkcs1_rsa_md5_encode(mpz_t m, size_t key_size, struct md5_ctx *hash)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(md5_prefix),
@@ -76,18 +77,23 @@ pkcs1_rsa_md5_encode(mpz_t m, size_t key_size, struct md5_ctx *hash)
     {
       md5_digest(hash, MD5_DIGEST_SIZE, p);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
 
 int
 pkcs1_rsa_md5_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(md5_prefix),
@@ -97,8 +103,12 @@ pkcs1_rsa_md5_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
     {
       memcpy(p, digest, MD5_DIGEST_SIZE);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
diff --git a/pkcs1-rsa-sha1.c b/pkcs1-rsa-sha1.c
index 781d75d9..c46b1b82 100644
--- a/pkcs1-rsa-sha1.c
+++ b/pkcs1-rsa-sha1.c
@@ -36,7 +36,7 @@
 #include "bignum.h"
 #include "pkcs1.h"
 
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 /* From pkcs-1v2
  *
@@ -65,8 +65,9 @@ int
 pkcs1_rsa_sha1_encode(mpz_t m, size_t key_size, struct sha1_ctx *hash)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha1_prefix),
@@ -76,18 +77,23 @@ pkcs1_rsa_sha1_encode(mpz_t m, size_t key_size, struct sha1_ctx *hash)
     {
       sha1_digest(hash, SHA1_DIGEST_SIZE, p);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
 
 int
 pkcs1_rsa_sha1_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha1_prefix),
@@ -97,8 +103,12 @@ pkcs1_rsa_sha1_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
     {
       memcpy(p, digest, SHA1_DIGEST_SIZE);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
diff --git a/pkcs1-rsa-sha256.c b/pkcs1-rsa-sha256.c
index a4d5bb1e..d41336f7 100644
--- a/pkcs1-rsa-sha256.c
+++ b/pkcs1-rsa-sha256.c
@@ -36,7 +36,7 @@
 #include "bignum.h"
 #include "pkcs1.h"
 
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 /* From RFC 3447, Public-Key Cryptography Standards (PKCS) #1: RSA
  * Cryptography Specifications Version 2.1.
@@ -63,8 +63,9 @@ int
 pkcs1_rsa_sha256_encode(mpz_t m, size_t key_size, struct sha256_ctx *hash)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha256_prefix),
@@ -74,18 +75,23 @@ pkcs1_rsa_sha256_encode(mpz_t m, size_t key_size, struct sha256_ctx *hash)
     {
       sha256_digest(hash, SHA256_DIGEST_SIZE, p);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;	
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
 
 int
 pkcs1_rsa_sha256_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha256_prefix),
@@ -95,8 +101,12 @@ pkcs1_rsa_sha256_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
     {
       memcpy(p, digest, SHA256_DIGEST_SIZE);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
diff --git a/pkcs1-rsa-sha512.c b/pkcs1-rsa-sha512.c
index 03acb690..0a67c108 100644
--- a/pkcs1-rsa-sha512.c
+++ b/pkcs1-rsa-sha512.c
@@ -36,7 +36,7 @@
 #include "bignum.h"
 #include "pkcs1.h"
 
-#include "nettle-internal.h"
+#include "gmp-glue.h"
 
 /* From RFC 3447, Public-Key Cryptography Standards (PKCS) #1: RSA
  * Cryptography Specifications Version 2.1.
@@ -63,8 +63,9 @@ int
 pkcs1_rsa_sha512_encode(mpz_t m, size_t key_size, struct sha512_ctx *hash)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha512_prefix),
@@ -74,18 +75,23 @@ pkcs1_rsa_sha512_encode(mpz_t m, size_t key_size, struct sha512_ctx *hash)
     {
       sha512_digest(hash, SHA512_DIGEST_SIZE, p);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
 
 int
 pkcs1_rsa_sha512_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
 {
   uint8_t *p;
-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
-  TMP_ALLOC(em, key_size);
+  TMP_GMP_DECL(em, uint8_t);
+
+  TMP_GMP_ALLOC(em, key_size);
 
   p = _pkcs1_signature_prefix(key_size, em,
 			      sizeof(sha512_prefix),
@@ -95,8 +101,12 @@ pkcs1_rsa_sha512_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
     {
       memcpy(p, digest, SHA512_DIGEST_SIZE);
       nettle_mpz_set_str_256_u(m, key_size, em);
+      TMP_GMP_FREE(em);
       return 1;
     }
   else
-    return 0;
+    {
+      TMP_GMP_FREE(em);
+      return 0;
+    }
 }
-- 
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